1. Field of the Invention
The present invention relates generally to a refrigeration purging system and more particularly to purge processors for low or high pressure refrigerant.
2. Description of Prior Art
Refrigerant tends to be expensive, as well as damaging to the environment. In the past, however, refrigerant containing chlorofluoronated carbons (CFC's) or halogenated chlorofluoronated carbons (HCFC's) was not so costly. As such, repairmen working on air conditioning or refrigeration systems would release refrigerant containing CFC's and HCFC's into the atmosphere and simply recharge the systems with new. Once the adverse impact such discharges had on the ozone layer became known, many governments began to prohibit the manufacture of CFC's and HCFC's.
In such an artificially inflated marketplace, refrigerant handling systems capable of recycling and/or reclaiming refrigerant became desirable. Most recycling machines have been equipped with air purge devices which vent air and other noncondensible contaminants from the refrigerant. Due to the fact that some refrigerant will mix with the air and noncondensibles, undesirable quantities of refrigerant are still being released into the atmosphere when purging occurs.
Within the United States, the quantity of refrigerant which can be purged into the atmosphere has been limited to no more than three percent by volume, according to The Clean Air Act, Section III, Sub-part e. Many attempts have been made to limit the quantity of refrigerant purged into the atmosphere during recycling and/or reclaim operations.
Examples of these attempts include U.S. Pat. No. 4,304,102 issued Dec. 8, 1981 to Gray; U.S. Pat. No. 5,241,837 issued Sep. 7, 1993 to Albertson, III; U.S. Pat. No. 5,355,685 issued Oct. 18, 1994 to Stie et al.; U.S. Pat. No. 5,367,886 issued Nov. 29, 1994 to Manz et al.; U.S. Pat. No. 5,338,416 issued Feb. 14, 1995 to Manz et al.; and U.S. Pat. No. 5,465,590 issued Nov. 14, 1995 to Van Steenburgh, Jr. et al.
Gray discloses a condenser with a float chamber, an evaporator, a compressor, a pair of purge chambers for purging the noncondensibles mixed with the refrigerant within the condenser, and a control system. The control system includes a differential pressure switch which measures the pressure drop across an orifice between the first purge chamber and a line ahead of the orifice. The differential pressure switch energizes a pump which circulates the gaseous mixture from the first to the second purge chamber. The pump also increases the pressure in the second purge chamber to aid in condensation.
Albertson, III discloses an auxiliary purge unit to be retrofitted to an existing purge unit of a low pressure refrigeration system. The auxiliary purge unit includes a condenser; compressor; evaporator; pneumatic chamber; discharge tank; and a double-walled condenser portion having a chilled condensing coil, a stand pipe, and an exhaust port. Albertson, III does not suggest when the noncondensible gases are to be purged from the exhaust port.
Stie et al. discloses a method of operating a purge system for a closed loop refrigeration unit with the aid of a programmable controller. The controller purges noncondensible gases once a difference between the actual and known vapor pressures of the refrigerant is greater than a desired value.
Manz et al. '886 and '416 disclose a refrigerant handling system and method with air purge and system clearing capabilities. The disclosure includes a pump which directs refrigerant through a condenser and into an air purge chamber. Air and other noncondensibles are purged, either manually or automatically, through a purge valve. A gauge serves in the determination of when such noncondensibles are to be purged.
Van Steenburgh, Jr. et al. discloses an air purge device including an evaporator contained within a chill chamber, a capillary tube, a filter drier, a solenoid valve, an insulated evaporator enclosure, a purge valve, and auxiliary devices. The disclosed device purges when a temperature differential between the side of the chill chamber and the evaporator outlet gradually increased, in lieu of using a "single shot" timer.
Other relevant patents include Japanese Publication Nos. 3-95370 on Apr. 19, 1991; and 4-316973 on Nov. 9, 1992; and Soviet Union No. 1041833 of Sep. 15, 1983.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the present invention as claimed. Thus a purge processor solving the aforementioned problems is desired.